1. Field of the Invention
The present invention relates to reduction of the thickness of a semiconductor device.
2. Description of the Related Art
In order to reduce product size and weight, there has in recent years been a determined effort towards reduction of the thickness of a semiconductor device components of such products.
In one conventional method for reducing the thickness of semiconductor devices, the back surface of a semiconductor device is mechanically ground. For example, a grinding method which uses a grinder is widely used due to its high productivity. Mechanical grinding of the back surface of a semiconductor substrate, however, may create crystal defects in the semiconductor substrate. Such crystal defects may extend so deep into the semiconductor substrate as to reach the front surface of the semiconductor substrate when the semiconductor substrate is excessively ground. Any such crystal defect severely affects the characteristics of an integrated circuit formed on the front surface of the semiconductor device.
According to another method for reducing the thickness of semiconductor devices, dry or wet etching is applied to a semiconductor substrate. Although the depth of crystal defects which result from use of this method are relatively shallow, the productivity of this method is low due to the slow etching speed.
In other words, for manufacture of a thin semiconductor substrate, the choices heretofore available are a highly-productive grinding method which mechanically grinds the back surface of a semiconductor device, but which causes deep crystal defects, and a method which uses dry or wet etching so as to minimize the occurrence of such crystal defects, but which suffers from poor productivity.